Most individuals with chronic HIV infection experience massive dysregulation of the immune system. Longlived memory B cells disappear, while immature B cells are hyperactivated and produce significant quantities of ineffective immunoglobulin. Furthermore, CD4 cells, the primary targets of HIV, steadily decline during the chronic phase of infection. Approximately 10-20% of HIV infected individuals overcome or escape this widespread immune dysfunction and produce broadly neutralizing antibodies to HIV. An understanding of how these indivduals generate broadly neutralizing antibodies to HIV is critical for HIV vaccine development. We hypothesize that H1V+ elite neutralizers have a less disrupted B lymphocyte compartment and/or an enhanced population of follicular helper CD4 T lymphocytes when compared to average or poorly neutralizing individuals. This hypothesis will be tested by multiparameter flow cytometric analysis of B and T lymphocyte populations at two early and two late time points post-infection, comparing indivuals who generate broadly neutralizing antibodies with average/poor neutralizers and uninfected individuals. The ability of B lymphocytes to differentiate into antibody secreting cells and the capacity of follicular T helper CD4 cells to produce important helper cytokines, such as IL-4 and IL-21, will also be compared in elite and poorly neutralizing individuals. These findings will help determine how elite neutralizers generate useful antibodies to HIV, and could greatly assist in the development of an effective HIV vaccine.